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Biology, Morphology and Taxonomy of Immature Stages of 9 Species in the Aspidiotini (Homoptera: Diaspididae)
Abstract
Life histories were studied for 9 aspidiotine species, one in the greenhouse and 8 in the field. Observations on the latter were made weekly when possible. The time of appearance and duration of each stage were determined and data were compiled for the species. As a result, seasonal history charts are presented and discussed for Abgrallaspis ithacae (Ferris), A. townsendi (Cockerell), Aspidiotus cryptomeriac Kuwana, Diaspidiotus liquidambaris (Kotinsky), D. mccombi McKenzie and Hemiberlesia lataniae (Newstead); seasonal development is discussed for Aspidiotus nerii Bouché, “Diaspidiotus” osborni (Newell and Cockerell) and Hemiberlesia diffinis (Newstead). Information on predators and parasites includes parasite emergence times.
There are keys to immature and adult stages and to 1st and 2nd instars of the 9 species studied.
Morphological features are discussed in detail for all immature stages and are illustrated. Specific characters are discussed for all immature stages and are illustrated for all 1st- and 2nd-instar males and 2nd-instar females.
Characters of the immature stages indicate that diffinis belongs in Hemiberlesia Cockerell instead of Abgrallaspis Balachowsky and that osborni is probably misplaced in Diaspidiotus Cockerell. The correct generic placement of osborni cannot be determined until the immature stages of additional species of the Aspidiotini are studied.
... Natural enemies usually control populations of latania scale in field conditions. However, this will only occur where insecticides are not applied (Stoetzel and Davidson, 1974). In New Zealand (1993) Hill et al. imported and released three predatory beetle species (Chilocorus bipustulatus (Linnaeus), C. infernalis (Linnaeus) and C. cacti (Linnaeus)) (Coleoptera: Coccinellidae) and two predatory mite species (Hemisarcoptes coccophagus Meyer and H. cooremani Thomas) for the biological control of armored scale insects including latania scale. ...
... The sexual dimorphism of first-instar nymphs in Diaspididae is well known. STOETZEL & DAVIDSON (1974a, 1974b noticed the setal pattern by which the sexes can be distinguished in all stages of the Aspidiotini tribe. They stated that all male stages possess a pair of dorsal submedian setae on the first and second abdominal segments, whereas these setae are missing in female instars. ...
The first instar of Diaspidiotus ostreaeformis is described and illustrated. Sexual dimorphism is exhibited. Differences between the first instars of D. ostreaeformis and D. zonatus are discussed.
Background: This study was realized for more than four years (from 2014 to 2018) in olive groves of northern Tunisian governorates. Scale insect samples were collected from leaves, stems and fruits.
Results: An annotated list of 22 scale insect species has been recorded. These species divided into 4 families. The family Diaspididae is the most species-rich, with 14 species in 9 genera; Coccidae contains 4 species in 3 genera; Pseudococcidae contains 3 species in 3 genera; and Asterolecaniidae contains 1 species in 1 genus.
Conclusions: This paper contains 3 species recorded for the first time in the Tunisian fauna: Saissetia coffeae (Walker), Diaspidiotus ostreaeformis (Curtis) and Lepidosaphes conchiformis (Gmelin).
Morphological differences and host preference in two forms of Aspidiotus cryptomeriae Kuwana associated with Cryptomeria japonica D. Don and Torreya nucifera Sieb. et Zucc. were examined in the Kanto district, Japan. Adult males and females showed statistically significant differences in some characters. However, it was impossible to divide specimens perfectly by using any one of these characters. Linear discriminant analysis using combinations of several characteristics successfully (>99%) discriminated them. Two sympatrical populations of adult females collected at the same stand were corrcctly classified by linear discriminant functions. Tests of forced host preference to five conifers indicated that each population was monophagous. The present study suggests strongly that these two forms are distinct host races. If the same holds true in other parts of Japan, these races might be considered to have differentiated into distinct species. © 1993, JAPANESE SOCIETY OF APPLIED ENTOMOLOGY AND ZOOLOGY. All rights reserved.
The first and second female and male instars of the white mango scale, Aulacaspis tubercularis Newstead (Coccoidea: Diaspididae), are described and illustrated. Morphological differences between the first and second instars of this species are compared and discussed. A key to differentiate between the first- and second-instars, key to sexual dimorphism in the first nymphal instars and key to sexual dimorphism in the second nymphal instars, were constructed.
The reproductive isolation between two host races of Aspidiotus cryptomeriae was examined by comparing intra- and inter-racial responses of males to live virgin females and to sex pheromones in the laboratory. No inter-racial copulation of males to live females was observed for either sex combination. These results indicated that ethological isolation was present between the races. We showed by using a crude extracts test that both host races have female sex pheromones. Although an inter-racial response of males to female extracts was observed, it was much weaker than the intra-racial responses, suggesting that the sex pheromone system plays an important role in reproductive isolation between the two races. These results support the hypothesis that each host race is a distinct species.
Uniparental (UP) and biparental (BP) populations of the oleander or ivy scale, Aspidiotus nerii Bouchè, were reared under similar conditions. Development of the UP population was always slower than that of the BP scales. UP females usually produced less than half the number of progeny the BP females had, and the patterns of development and oviposition were quite dissimilar.The shield of UP females was slightly, but consistently, darker than that of BP females, and the latter never colonized Pittosporum undulation, the only host-plant on which UP population occur in Israel. These criteria are used to describe the uniparental population as Aspidiotus paranerii Gerson sp. nov. and to differentiate it from A. nerii. As the biology of A. paranerii clearly differs from that of a Californian uniparental sibling species of A. nerii, it is argued that the latter may have a series of such parthenogenetic relatives.
A quantitative comparison of the classifications of 24 species of male Diaspididae by principal component and principal coordinate analysis was extended to allow the comparison of classifications based on selected subsets of the 101 available characters. It was shown that subsets of 25–28 characters could be chosen numerically and used to construct classifications that resembled very closely the classification based on the reference set of characters. The conclusions are discussed in relation to other views on character-weighting and in relation to classifications of the Diaspididae based on traditional taxonomic characters provided by the females.
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